This invention relates to surgical devices including an over the needle catheter for insertion into the tissues of a body cavity of a patient for the introduction or removal of fluids. Such devices are most commonly intended for intravascular use, particularly for infusion purposes, although various other uses are quite common, such as drainage tubes and so forth. After insertion into the body of a patient the catheter is generally connected by a length of tubing to a container for the fluid which is to be introduced or withdrawn. Since the catheter will normally need to be left in position for at least several hours, it must be resilient and efficiently shaped for the introduction of fluid or removal of fluid.
More specifically the shape of the catheter tip must be such that little trauma is incurred during insertion and once in place the resilient catheter will not damage internal tissues of the blood vessel. Consequently if the catheter is to remain in position for a long period of time, it is more comfortable for the patient if it is made of a relatively soft pliable material. Therefore, the catheter device needs to be included with a removable introducer needle fitted coaxially within the catheter in order to puncture the skin and penetrate the vessel permitting the subsequent over the needle introduction of the catheter into the blood vessel. The introducer needle needs to project slightly beyond the end of the catheter so that shortly after the introducer needle has pierced the skin of the patient the catheter may then pass therewith through the same perforation and once the catheter has been slid along the needle into position the introducer needle can then be removed by coaxially withdrawing the needle from within the inserted catheter.
It has been the problem with devices of this type to produce a catheter material which is suitably resilient and strong and has a tapered tip which permits insertation over the introducer needle. More specifically, the catheter body has to be of high strength and thin wall in order to permit maximum fluid flow yet the tip requires a specific design to permit ease of introduction along with the needle.
It is an object of the present invention to teach a method of providing a catheter configuration which is easily inserted into a patient's blood vessel thereby minimizing trauma and injury.
It is yet another object of present disclosure to illustrate a configuration and a material which permits a high rate of fluid flow and maximum strength with requisite flexibility to be comfortable for the patient during use.